Answer:
Many
Homogenous
There are no barriers
Have perfect knowledge
Step-by-step explanation:
A perfect competition is characterised by many buyers and sellers of homogenous goods. Because there are many sellers of homogenous goods, firms are price takers.
Because there are no barriers to entry, in the long run, firms earn zero economic profit.
Because buyers and sellers have perfect knowledge of prices, price arbitrage isn't possible.
I hope my answer helps you.